Safety Magazine

ABSTRACT

The present invention relates to magazines for firearms, and more particularly to magazines that accept blank cartridges for training and other exercises and that prevent the introduction of live cartridges. In an embodiment, the safety magazine includes an internal cavity that is shorter in length than a live ammunition cartridge. The internal cavity accepts shorter blank ammunition cartridges. The top-most ammunition cartridge in the magazine sits just under the magazine&#39;s feed lips, in the top-most ammunition position. A projection extends from the top end of the magazine opposite the feed lips to block a longer live ammunition cartridge from being inserted into the top-most ammunition position. Thus, live cartridges cannot be loaded into the magazine even at the top-most position of the magazine. The projection is retractable into the magazine.

FIELD OF THE INVENTION

The present invention relates to magazines for firearms, and more particularly to magazines that accept blank ammunition cartridges for training and other exercises and that prevent the introduction of live ammunition cartridges.

BACKGROUND

Military, police, and other armed forces often use firearms with blank ammunition cartridges during training exercises. The individuals participating in the training exercise load the blank cartridges into a magazine and attach the magazine to their firearm. Use of the blank cartridges enables the participants to use their regular firearms as if the training exercise were a real combat situation, but the participants are not firing live rounds. As a result, the participants can practice with real firearms without risking any harm to themselves or other participants. The training exercise is realistic but safe.

However, occasionally a participant will accidentally insert a magazine with live ammunition into the firearm, or will accidentally load a live cartridge into a magazine along with or instead of blank cartridges. Such a mistake can have deadly consequences during a training exercise.

In the past, training participants have used a safety magazine having an internal cavity which is shorter in length than that of a normal magazine and that accepts only blank cartridges. Blank ammunition cartridges are typically shorter in length than live ammunition cartridges because the blank cartridges lack a bullet at the front end. Such a safety magazine is disclosed in U.S. Pat. No. 4,777,752. However, this magazine still accepts a longer live cartridge in the top-most position of the magazine. Even though the internal cavity of the magazine is shorter than a standard live ammunition cartridge, the magazine still accepts a longer live round as the last cartridge loaded into the magazine at the top-most position or position, below the magazine's feed lips.

In the past, training exercises have also utilized safety magazines that are pre-loaded with blank cartridges and that cannot be re-loaded after they are used. The magazine can eject the blank cartridges but cannot accept any new cartridges for re-use. Thus, the user cannot insert a live round into the magazine. Such a safety magazine is disclosed in WO 2005/083348. However, this magazine is not re-usable.

Accordingly, there is still a need for a reusable safety magazine that precludes the insertion of live cartridges into the magazine.

SUMMARY OF THE INVENTION

The present invention relates to magazines for firearms, and more particularly to magazines that accept blank cartridges for training and other exercises and that prevent the introduction of live cartridges. In an embodiment, the safety magazine includes an internal cavity that is shorter in length than a live ammunition cartridge. The internal cavity accepts shorter blank ammunition cartridges. The top-most ammunition cartridge in the magazine sits just under the magazine's feed lips, in the top-most ammunition position. A projection extends from the top end of the magazine opposite the feed lips to block a longer live ammunition cartridge from being inserted into the top-most ammunition position. Thus, live cartridges cannot be loaded into the magazine even at the top-most position of the magazine. The projection is retractable into the magazine. When the magazine is inserted into a firearm, the bottom surface of the firearm pushes down and retracts the projection, so that the projection will not interfere with the loading of the blank cartridges into the firearm chamber. When the magazine is removed from the firearm, the projection returns to the extended position, blocking the top-most ammunition position, so that live cartridges cannot be inserted into the magazine.

In one embodiment, a magazine for a firearm includes a housing having first and second opposing side walls and an internal cavity between the side walls. The internal cavity is sized to receive blank ammunition cartridges and has an opening at a top end of the housing for receiving such cartridges into the cavity. The magazine also has a follower for moving the cartridges toward the top end of the housing into a top-most ammunition position. The magazine also has a projection movable between a first position in which the projection extends into the top-most ammunition position and a second position in which the projection is retracted out of the top-most ammunition position, and an extension coupled to the projection and extending through an opening in the first side wall of the housing. A spring biases the projection into the first position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will become appreciated as the same become better understood with reference to the specification, claims and appended drawings wherein:

FIG. 1 is a perspective view of a safety magazine in an extended or blocking position according to an embodiment of the invention.

FIG. 2 is a perspective view of the safety magazine of FIG. 1 in a retracted position.

FIG. 3A is a perspective view of a top portion of a safety magazine in an extended position according to an embodiment of the invention.

FIG. 3B is a perspective view of a bottom portion of a safety magazine according to the embodiment of FIG. 3A.

FIG. 3C is a top view of the top portion of FIG. 3A.

FIG. 3D is a top view of the bottom portion of FIG. 3B.

FIG. 3E is a partial perspective view of a spacer according to the embodiment of FIG. 3B.

FIG. 4A is a partial perspective view of a safety magazine in an extended position, according to an embodiment of the invention.

FIG. 4B is a partial perspective view of the safety magazine of FIG. 4A, in a retracted position.

FIG. 5A is a partial perspective view of a safety magazine in an extended position, according to an embodiment of the invention.

FIG. 5B is a side elevational view of the safety magazine of FIG. 5A before insertion into a firearm.

FIG. 5C is a side elevational view of the safety magazine of FIG. 5A, partially inserted into a firearm.

FIG. 5D is a top perspective view of the safety magazine of FIG. 5A inserted into a firearm, in a retracted position.

FIG. 5E is a top perspective view of the safety magazine of FIG. 5A inserted into a firearm, during loading of a cartridge into the firearm.

FIG. 6 is a side view of a top portion of a safety magazine, with one side removed, according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to magazines for firearms, and more particularly to magazines that accept blank cartridges for training and other exercises and that prevent the introduction of live cartridges. In an embodiment, the safety magazine includes an internal cavity that is shorter in length than a live ammunition cartridge. The internal cavity accepts shorter blank ammunition cartridges. The top-most ammunition cartridge in the magazine sits just under the magazine's feed lips, in the top-most ammunition position. A projection extends from the top end of the magazine opposite the feed lips to block a longer live ammunition cartridge from being inserted into the top-most ammunition position. Thus, live cartridges cannot be loaded into the magazine even at the top-most position of the magazine. The projection is retractable into the magazine. When the magazine is inserted into a firearm, the bottom surface of the firearm pushes down and retracts the projection (as shown in FIGS. 2, 4B, and 5C-5E and discussed below), so that the projection will not interfere with the loading of the blank cartridges into the firearm chamber. When the magazine is removed from the firearm, the projection returns to the extended position, blocking the top-most ammunition position, so that live cartridges cannot be inserted into the magazine.

In an embodiment, a safety magazine 10 includes an outer housing 12 with a top end 14, bottom end 16, front end 26, and back end 24, as shown in FIG. 1. The magazine also includes an internal cavity 18 that receives and stores blank cartridges 28. The blank cartridges are inserted into the internal cavity 18 through an opening 20 at the top of the cavity 18, where the cavity meets the top end 14 of the housing. The blank cartridges are inserted in the direction of arrow A between the curved feed lips 22 that curve over the opening 20, and the cartridges are then pushed down into the cavity 18. The feed lips 22 are positioned near the back end 24 of the housing 12, opposite the front end 26. The last cartridge 28 loaded into the magazine 10 occupies the top-most ammunition position 19, just above the cavity 18 and under the feed lips 22.

The internal cavity 18 is dimensioned to receive blank ammunition cartridges 28 and to exclude live ammunition cartridges. Blank cartridges are shorter than live cartridges because they lack a projectile. Live cartridges include a housing or casing filled with gun powder, with a primer at the back of the casing and a bullet or projectile seated at the open front end of the casing. Blank cartridges include a casing filled with gun powder and primer, but the front end of the casing is crimped shut, and there is no projectile or bullet. As a result, these cartridges are shorter in length than live cartridges, by about the length of the bullet. For example, live cartridges measure about 2.25 inches in length, and blank cartridges 1.8 inches. The term “blank cartridge” is used herein to refer to cartridges that lack a bullet or projectile at the front end of the cartridge.

The opening 20 at the top of the cavity 18 has a length L_(c) (see FIG. 2) that is designed to receive blank cartridges 28 having length L_(B) (see FIG. 1). The length L_(c) is at least as long as L_(B) (typically slightly longer, to provide a tolerance around the sides of the blank cartridges 28 so they can move up and down inside the cavity) but is less than the length of a standard live ammunition cartridge by about the length of a bullet. For example, in one embodiment the length L_(c) is less than 2 inches, and in another less than or about 1.9 inches. Therefore live cartridges cannot be inserted into the cavity 18 through the opening 20. The cavity 18 extends from the back end 24 of the housing to an internal wall 46. This wall 46 shortens the length of the cavity 18, such that the cavity does not extend all the way to the front end 26 of the housing 12. In one embodiment, the wall 46 extends from the bottom end 16 to the top end 14 of the cavity 18, as shown in FIG. 1.

However, even with the cavity 18 and opening 20 shortened to length L_(c) to preclude insertion of a live cartridge, the last cartridge inserted into the magazine into the top-most position 19 could potentially be a live cartridge, as the top-most position 19 has a length L_(T) (see FIG. 2) that can accept a longer live cartridge. The back end of the live cartridge could be inserted below the feed lips 22, with the longer front end of the cartridge extending over and past the wall 46. The live cartridge may have to be tilted slightly to fit under the feed lips 22 and over the wall 46. However, the safety magazine 10 also includes a movable piece or movable stop 40 (see FIG. 1) that shortens this top-most position 19 to prevent the introduction of a live cartridge as the last cartridge inserted into the magazine.

In the embodiment of FIGS. 1-2, the movable stop 40 is a T-shaped piece having a projection 42 and an extension 50, as shown in FIG. 1. The projection 42 extends up through an opening 54 in top surface 30 at the top end 14 of the housing, in front of the feed lips 22, cavity 18, opening 20, and wall 46. The projection 42 extends into the front end of the top-most position 19, shortening the top-most position by occupying its front end. The projection 42 thereby blocks a longer live cartridge from being inserted into the top-most position 19. The projection 42 may be a rod, shaft, finger, or other suitable structure that extends into this location 19 and sits in front of the top-most blank cartridge. The projection may have any suitable shape, such as circular, square, triangular, trapezoidal, semi-circular, or other shapes.

The movable stop 40 with projection 42 slides up and down within a second internal cavity 44 at the front end 26 of the housing 12. The two cavities 18, 44 are separated by the internal dividing wall 46. The first internal cavity 18 is located between the wall 46 and the back end 24 of the housing 12. The second internal cavity 44 is located forward of the first cavity, between the wall 46 and the front end 26 of the housing.

The projection 42 is coupled to an extension such as a peg 50, which extends in opposite directions through openings such as slots 52 in side walls 32, 34 of the housing 12, as shown in FIGS. 1 and 2 (the slot shown on only one side in each figure). The peg 50 and projection 42 move together, sliding up and down in the second internal cavity 44. The extension may be two pegs 50, one extending out each side of the magazine, or it may be a single peg that extends through both sides of the magazine, or it may be a single peg that extends through only one side of the magazine. The extension 50 may be any suitable structure that extends out from one or both sides of the magazine to engage the firearm. The extension 50 is coupled to the projection 42. For example, the peg 50 may pass through a hole or passage in a lower end of the movable stop 40, or it may be threaded, adhered, or otherwise attached to a lower end of the stop 40. It can be formed of two separate pieces, with one piece inserted into the slot on each side of the housing.

Notably, positioning the slot 52 and peg 50 to extend through a side wall of the housing, rather than, for example, the front wall 26, is beneficial in the event that the user attaches an accessory device such as a grenade launcher in front of the magazine. The peg extending out the side wall 32 or 34 of the housing will not interfere with an accessory device or other features on the firearm in front of the magazine well, and in front of front wall 26 when the magazine is loaded into the firearm.

A spring 56 (partially shown in dotted lines in FIG. 2) biases the movable stop 40 toward the top end 14 of the housing, causing the projection 42 to extend through the opening 54 and up into the front of the top-most position 19. This extended position is shown in FIG. 1, with the projection 42 extending into the front of the top-most position 19, and the peg 50 positioned at an upper portion 52 a of the slot 52. Unless a force acts against the spring 56, the spring naturally forces the movable piece 40 into this extended position, with the projection 42 blocking the front end of the top-most ammunition position 19. In one embodiment, the spring is housed with the movable stop 40 inside the second internal cavity 44.

With the projection 42 extending in front of the opening 20 at the top of the cavity 18, the projection shortens the length of the top ammunition position 19. As a result, the user will not be able to load a live ammunition cartridge into the magazine. The front end of the live ammunition round, with the bullet or projectile, is too long to fit inside the cavity 18 and behind the projection 42.

However, if the projection 42 were permanently extended, in the position shown in FIG. 1, it could interfere with the proper loading of the blank cartridges into the firearm chamber for firing, in the direction of arrow B. When the magazine 10 is inserted into a magazine well in a firearm, the firearm engages the top-most cartridge and pushes it forward, in the direction of the arrow B, into the firearm chamber. If the projection 42 extended up into the top-most position 19, it could block the cartridges from moving forward into the firearm chamber.

Accordingly, the projection 42 is designed to retract into the second internal cavity 44 or otherwise move out of its extended position when the magazine is inserted into a firearm. The firearm has an opening through which the top end 14 of the magazine 10 is inserted into the firearm's internal magazine well. The outer dimensions of the safety magazine 10 are the same as a standard magazine, so that the safety magazine 10 will fit into a standard firearm magazine well. Thus, the safety magazine can be used with standard firearms, to give the training participant realistic experience using the same firearm that will be used for real combat exercises.

When the magazine is inserted into the firearm, the surrounding bottom surfaces 60 of the firearm pass around the sides of the magazine, as shown by the dotted lines in FIG. 2 (also shown in FIGS. 5B-C). The bottom surface 60 of the firearm contacts the peg 50 extending from the sides of the magazine and pushes the peg down, as shown in FIG. 2. In this retracted position, the peg 50 has moved to a lower portion 52 b of the slot 52, compressing the spring 56. The projection 42 moves along with the peg, and is retracted into the second internal cavity 44. With the movable piece 40 in this retracted position, the projection 42 no longer extends into the front end of the top-most position 19. As a result the projection will not interfere with smooth loading of the blank cartridges from this top-most position into the firearm chamber. In other embodiments, the projection can be pushed to the side or otherwise moved out of the extended position so that it no longer blocks the front of the top-most position and the loading of blank cartridges into the firearm.

When the magazine is removed from the firearm, the spring 56 urges the peg 50 back up to the upper portion 52 a of the slot 52, causing the projection 42 to extend through the opening 54 into the extended position shown in FIG. 1, once again preventing a user from loading live cartridges into the magazine. Thus, whenever the magazine is removed from the firearm, the projection 42 extends up and blocks the loading of live cartridges. Whenever the magazine is loaded into the firearm, the projection 42 retracts so that it does not interfere with loading the blank cartridges into the firearm.

Notably, due to manufacturing and operating constraints, there will likely be some clearance such as distance C (see FIGS. 2 and 3C) between the end of the cavity 18 and the beginning of the projection 42. This clearance C is shorter than the length of a bullet or projectile, such that a live ammunition cartridge cannot fit in the combined length of L_(c) and C. That is, the length of a live ammunition cartridge is greater than L_(c)+C. As a result, the projection 42 blocks a live cartridge in the top-most ammunition position.

The safety magazine 10 can be made out of any suitable material. In one embodiment, the magazine is formed out of a suitable high-impact polymer, such as Celstran, manufactured by Ticona, a division of the Celanese Corporation. In another embodiment, the magazine is formed from metal. The choice of material may depend on the training scenario and objectives.

The magazine 10 also includes a spring-biased follower 62 that guides the blank ammunition cartridges 28 toward the feed lips 22, as shown in FIG. 1. The follower 62 is urged toward the top of the housing by a compressed spring 64 between the bottom of the magazine and the follower. The follower evenly distributes the force of the compressed spring across most of the length of the cartridges and directs the cartridges into the feed lips 22. The follower is not shown in FIG. 2, for clarity. The follower 62 may be slightly shorter than the follower used in a live-capacity magazine, due to the shortened length of the cavity 18.

The feed lips 22 are a guide that feed the blank cartridges from the top-most position 19 into the firearm chamber, as is well known in the art. The feed lips guide the cartridges and keep them aligned for movement into the firearm chamber. The feed lips also retain the cartridges in the magazine, keeping them in place and in alignment as the follower 62 urges them to the top of the magazine. In one embodiment, the feed lips extend up from the top edge 36 of the housing by about 0.375 inches.

Another embodiment of a safety magazine 100 is shown in FIGS. 3A-3E. In these figures, the magazine 100 includes an outer housing 112 that is formed from two halves or portions, a top portion 102 and bottom portion 104. The two portions are attached together, such as by inserting the bottom end of the top portion 102 into the open top end of the bottom portion 104. The two portions can be secured together by inserting projections 166 near the bottom of the top portion 102 into recesses 168 on the inside surface at the top end of the bottom portion 104. Optionally, the two portions 102, 104 are adhered together. This two-part design is beneficial because, as described in more detail below, the top portion 102 can be modified to prevent the introduction of live rounds, while the bottom portion 104 is manufactured the same way for both live magazines and safety magazines. That is, the same bottom portion 104 that is manufactured for live cartridges can be also used in the safety magazine 100, thus reducing manufacturing and design costs.

The top portion 102 has an internal cavity 118. This cavity 118 is sized for shorter blank cartridges and is too short to accept longer live cartridges. At the top of the magazine is the top-most ammunition position 119. Although the top-most position or location 19, 119 is described as being at the top end of the magazine above the internal cavity 18, 118, it should be understood that a blank cartridge 28 sitting in this top-most position 19, 119 may extend partly into the cavity 18, 118. The top-most position 19, 119 refers to the position of the top-most cartridge in the magazine, directly under the feed lips 22, 122.

A spring-biased follower urges the cartridges 28 toward the top-most position 119 as described above with respect to FIGS. 1-2. The follower is not shown in FIGS. 3A-3F, for clarity. The follower guides the cartridges 28 into the feed lips 122 for loading into the firearm. As shown in FIGS. 3C and 3D, the cartridges are staggered inside the magazine, in order to more compactly store them inside the internal cavity 118, 118′. The follower shown in FIG. 1 has a projection 63 positioned on one side of the top surface of the follower, which nudges the first cartridge to one side in order to initiate the staggering of the cartridges loaded above it.

The interior walls of the bottom portion 104 (and optionally the top portion, as shown in FIG. 6) have a ridge 172 that extends into the cavity 118 on both sides of the magazine, as shown in FIGS. 3B and 3D. The cartridges 28 contact this ridge 172 and ride along the ridge as they move up and down within the cavity 118. The ridge 172 distances the cartridges 28 from the internal walls of the housing 112, in order to reduce friction between the cartridges 28 and the internal walls of the housing.

The top portion 102 includes an internal wall 146 that divides the first internal cavity 118 from a second internal cavity 144 near the forward end of the top portion. The second internal cavity 144 includes a floor 148 at the bottom end of the top portion 102. A movable piece or movable stop 140 slides up and down inside the second cavity 144, similar to the movable stop 40 described above in FIGS. 1-2. A spring 156 urges against the floor 148 of the top portion and biases the stop 140 into an extended position, as shown in FIG. 3A. The stop 140 includes an extension such as a peg 150 that extends through an opening such as a slot 152 in the top portion 102. Movement of the peg 150 in the slot 152 constrains the movement of the movable piece 140, preventing it from exiting the top portion 102. The projection 142 and peg 150 can be formed together as one integral piece, or they can be separate pieces that are coupled together.

The top end of the movable stop 140 forms a projection 142 that moves in front of the top-most blank round 28 when the spring 156 biases the movable stop 140 into the extended position. The projection 142 blocks the front end of the top-most position 119, shortening this ammunition position 119 and precluding the insertion of a live cartridge into this position. When the magazine is loaded into a firearm, the bottom surface of the firearm pushes the peg 150 down into the bottom portion of the slot 152. As the peg 150 moves down, the projection 142 is retracted into the cavity 144. In this retracted position, the blank rounds 28 can move forward past the projection 142 and into the firearm to be fired.

In one embodiment, the spring 156 that urges the projection 142 into the extended position is strong enough to displace a live ammunition cartridge if a user tries to manually hold the projection 142 down in the retracted position and insert a live cartridge into the top-most position 119, with the front end of the live cartridge extending above the retracted projection 140. When the user inserts the magazine into a firearm (as shown, for example, in FIGS. 5B-5C), the user releases the projection 142, at which point the spring 156 urges the projection 142 upward against the live cartridge in the top-most position 119. In an embodiment, the spring 156 applies sufficient force to displace the live ammunition cartridge from the position 119. Thus, the safety magazine successfully prevents the introduction of a live cartridge. In an embodiment, the force required to retract the projection against the force of the spring 156 is about 75 ounces.

In the embodiment shown in FIG. 3A, the projection 142 extends to a height H above the top edge 136 of the top portion 102 in the extended position. In the extended position, the top of the projection 142 forms an angle A with the top forward end of the feed lips 122. As the height H increases, the angle A also increases. In one embodiment, the height H is large enough to create an angle A of about 15°, and in another embodiment about 20°, and in another embodiment about 25°. In other embodiments the angle A may range between about 15-20°. An angle A of about 15° or larger helps to prevent a user from loading a live cartridge into the magazine by tilting the back end of the cartridge below the feed lips 122 and the front of the cartridge over the projection 142. Such insertion of a live cartridge is made more difficult with a large angle A. If the cartridge is wedged into the magazine at too steep an angle, it will not feed properly into a firearm. In one embodiment, the height H is approximately 0.625 inches, and in another embodiment, about 0.75 inches. In one embodiment, the height H is approximately three times the height of the feed lips 122 above the top edge 136.

In an embodiment, the internal cavity 144 extends along the length of the top portion 102, from the top end 114 to the floor 148. The cavity 144 does not extend all the way along the length of the magazine 100, as it does not extend into the bottom portion 104.

The bottom portion 104, as shown in FIG. 3B, is the same bottom portion used for live ammunition cartridges, with an internal cavity 118′ that is long enough to receive live cartridges. In order to prevent the insertion of live cartridges into the bottom portion 104, a spacer 170 is inserted into the forward end 126 of the bottom portion 104. The spacer 170 is shown in FIGS. 3D and 3E. In an embodiment, the spacer 170 is a hollow block that is contoured to match the bottom portion 104. That is, if the bottom portion 104 is curved in a horizontal or vertical plane, the spacer is contoured to match such curves. The spacer is hollow in order to reduce the cost and weight of the spacer, although in other embodiments it is solid. The spacer 170 is sized such that when inserted into the bottom portion 104, it shortens the cavity 118′ to block the introduction of live ammunition cartridges. That is, the length of the cavity 118′ minus the length L_(s) of the spacer is too short to receive a live cartridge, but long enough to receive a blank cartridge. The height of the spacer is about the same as the height of the bottom portion 104. The spacer can be made out of any suitable light-weight material such as a molded polymer.

The spacer 170 is inserted into the bottom portion 104 in front of the ridge 172, before the bottom portion 104 is attached to the top portion 102. When the top portion 102 is attached, the floor 148 traps the spacer 170 into place between the floor 148 and the ridges 172. Optionally, adhesive such as glue is used to further secure the spacer 170 in place. With the simple insertion of this spacer 170, the bottom portion 104 is ready to be used in the safety magazine. Thus, the bottom portion 104 can be manufactured the same way for both live cartridges and blank cartridges, thereby reducing design and manufacturing costs.

Another embodiment of the invention is shown in FIGS. 4A-4B. In this embodiment, a safety magazine 200 includes a movable stop 240 that slides up and down within an internal cavity 244. The movable stop 240 includes a peg 250 and a projection 242. The projection 242 includes a sloped surface 238 that forms a ramp along the top of the projection 242. In the extended position shown in FIG. 4A, the projection 242 extends above the feed lips 222 and shortens the top ammunition location 219, as described with respect to earlier figures. In the retracted position shown in FIG. 4B, the projection 242 forms a ramp that assist in the feeding of the blank cartridges into the firearm. The blank cartridge 28 have a blunt front end, so the ramp assist in guiding the cartridges forward without becoming jammed. The internal wall 246 dividing the chambers 244 and 218 is lowered slightly, to provide access to the ramp 238, as shown in FIG. 4B. In one embodiment, the ramp 238 is sloped at an angle of approximately 10>.

Another embodiment is shown in FIGS. 5A-5E, which show the progression of loading and firing a firearm. A safety magazine 300 is shown in FIG. 5A, with the movable stop 340 in the extended position, blocking the insertion of live cartridges into the magazine, including into the top-most position 319. FIG. 5A also shows the staggered configuration of the blank cartridges inside the magazine, as described earlier. FIG. 58 shows the magazine 300 before insertion into a firearm 306 having magazine well 308. The movable stop 340 is in the extended position, with the peg 350 at the top of the slot 352.

In FIG. 5C, the magazine 300 is partially inserted into the firearm 306. The bottom surfaces 360 of the firearm 306, around the magazine well 308, contact the peg 350 and push it toward the bottom of the slot 352, retracting the movable piece 340 into the internal cavity 344. FIG. 5D shows the magazine 300 fully inserted into the firearm 306. The movable stop 340 is retracted into the magazine, clearing a path for the top-most blank cartridge to move forward into the firearm chamber. This movement is shown in FIG. 5E. The blank cartridge moves over the top of the retracted stop 340 and into the firearm chamber for firing.

In one embodiment, the stop 340 retracts only so far as to allow chambering of the cartridges into the firearm. The stop 340 retracts substantially out of the top-most position, but continues to block the insertion of live cartridges below the top-most position. Thus, even with the projection retracted, the second position 317 just below the top-most position 319 is blocked by the stop 340 and/or the internal wall 346. This can be seen in the embodiment shown in FIG. 5E, where the movable stop 340 has retracted just enough to allow passage of the top-most cartridge into the firearm chamber. In this retracted position, the stop 340 continues to act as a block to prevent a user from attempting to insert a live cartridge into the magazine.

Another embodiment is shown in FIG. 6. In this embodiment, a top portion 402 of a safety magazine includes a movable piece or stop 440 with a tapered or triangular projection 442. The movable piece 440 is shaped as a hollow member with a rectangular cross-section and a triangular top end 442. A peg 450 extends through a hole in the stop 440 and extends through a slot (not shown in this figure) in the top portion 402. The top portion 402 also includes a groove 474 that extends along the height of the top portion 402 and aligns with the back end of the cartridges 28, to help guide them up within the top portion 402 toward the feed lips 422.

The embodiments described above show that the projection (42, 142, 242, 342, 442), extension or peg (50, 150, 250, 350, 450), and movable stop (40, 140, 240, 340, 440) can take different shapes and sizes. However these elements are shaped and arranged inside the magazine, the invention provides for a safety magazine that does not accept live cartridges, even in the top-most position of the magazine.

Where used throughout the specification and figures, like reference numbers indicate like elements or features.

Although the present invention has been described and illustrated in respect to exemplary embodiments, it is to be understood that it is not to be so limited, since changes and modifications may be made therein which are within the full intended scope of this invention as hereinafter claimed. 

1. A magazine for a firearm, comprising: a housing comprising first and second opposing side walls and an internal cavity between the side walls, the internal cavity being sized to receive blank ammunition cartridges and having an opening at a top end of the housing for receiving such cartridges into the cavity; a follower for moving such cartridges toward the top end of the housing into a top-most ammunition position; a projection movable between a first position in which the projection extends into the top-most ammunition position and a second position in which the projection is retracted out of the top-most ammunition position; an extension coupled to the projection and extending through an opening in the first side wall of the housing; and a spring biasing the projection into the first position.
 2. The magazine of claim 1, wherein the opening in the first side wall comprises a slot, and wherein the projection is in the first position when the extension is in an upper portion of the slot, and the projection is in the second position when the extension is in a lower portion of the slot.
 3. The magazine of claim 1, wherein the projection is housed within a second internal cavity in the housing, and wherein the first and second internal cavities are divided by an internal wall.
 4. The magazine of claim 3, wherein the spring is located within the second internal cavity.
 5. The magazine of claim 1, wherein the projection comprises a sloped top surface.
 6. The magazine of claim 1, wherein the housing comprises a guide at the top end of the housing for guiding such cartridges into such firearm.
 7. The magazine of claim 6, wherein the projection extends above the guide when the projection is in the first position.
 8. The magazine of claim 7, wherein the projection extends above the guide by at least 25 inches.
 9. The magazine of claim 7, wherein an angle between a top end of the projection and a forward end of the guide, when the projection is in the extended position, is at least 15°.
 10. The magazine of claim 1, wherein the internal cavity has a length that is less than a length of a live ammunition cartridge.
 11. The magazine of claim 10, wherein the internal cavity has a length less than approximately 2 inches.
 12. The magazine of claim 1, wherein in the second position, the projection blocks a second ammunition position below the top-most position, to prevent the insertion of a live ammunition cartridge into the second position.
 13. The magazine of claim 1, wherein the spring exerts a force against the projection sufficient to prevent insertion of a live cartridge into the magazine.
 14. A magazine for a firearm, comprising: a housing comprising: a top portion comprising a first internal cavity sized to receive blank ammunition cartridges, a second internal cavity, an internal wall separating the first and second cavities, and a top-most ammunition position at a top end of the top portion; and a bottom portion attached to the top portion, the bottom portion comprising an internal cavity and a spacer positioned in the internal cavity to shorten the internal cavity to receive blank ammunition cartridges; a movable piece positioned in the second cavity of the top portion, the movable piece having a projection, wherein the movable piece is slidable between an extended position in which the projection extends into the top-most ammunition position and a retracted position in which the projection is retracted into the second cavity; and a spring biasing the movable piece into the extended position.
 15. The magazine of claim 14, wherein the movable piece further comprises a peg extending through a slot in the top portion of the housing, and wherein the peg is engagable with a firearm to move the projection into the retracted position.
 16. The magazine of claim 14, wherein the projection comprises a sloped top surface.
 17. A safety magazine comprising: a housing having an internal cavity sized to receive blank ammunition cartridges, the cavity having an opening for receiving such cartridges into the cavity, the housing comprising a guide for retaining a cartridge in a top-most ammunition position at a top end of the housing; and means for shortening the top-most ammunition position to prevent the insertion of a live ammunition cartridge.
 18. The magazine of claim 17, wherein the means for shortening the top-most ammunition position comprises a projection movable into an extended position in which the projection shortens a length of the top-most ammunition position, and a second internal cavity in which the projection moves.
 19. The magazine of claim 18, wherein the projection comprises a ramp at a top end of the projection for guiding such cartridges into a firearm.
 20. The magazine of claim 19, wherein the ramp is angled at about 10°. 